Gastric space fillers used for achieving loss of weight in extremely obese persons have been known in the prior art. All gastric space fillers utilized for this purpose function on the principles that an empty bag or space filler is placed into the stomach through the esophagus. Thereafter, the bag or space filler is filled (fully or partially) with a suitable insufflation fluid, such as saline solution, through a filler tube or catheter, which is inserted into the stomach through the mouth or the nose. The space filler occupies space in the stomach thereby leaving less room available for food and creating a feeling of satiety for the obese person. Clinical experience of the prior art has shown that for many obese patients the intragastric space fillers significantly help to control appetite and accomplish weight loss.
Garten et al in U.S. Pat. Nos. 4,416,267 and 4,899,747, entire contents of which are incorporated herein by reference, discloses a stomach insert for treating obesity in humans by reducing the stomach volume comprising a flexible, torus-shaped inflatable space filler having a central opening extending therethrough. At least a portion of the space filler has a self-sealing substance to facilitate puncture thereof with a needle for inflating the space filler and sealing off the puncture upon removal of the needle. The method herein comprises positioning the space filler inside the stomach of the person being treated for obesity so as to reduce the stomach volume. The Garten et al. stomach insert works satisfactorily to control the appetite. However, the insert may cause nausea and uncomfortable side effects. It appears desirable to have a space filler system that could reduce nausea caused by intragastric balloons for treatment of morbid obesity of a patient.
Several surgical techniques have been tried which bypass the absorptive surface of the small intestine or aim at reducing the stomach size by either partition or bypass. These procedures have been proven both hazardous to perform in morbidly obese patients and have been fraught with numerous life-threatening postoperative complications. Moreover, such operative procedures are often difficult to reverse.
Non-surgical approaches for the treatment of obesity include voluntary dieting which is often unsuccessful since most persons do not possess sufficient willpower to limit the intake of food. Other approaches include the use of stomach fillers such as methylcellulose (MC), often taken in the form of tablets. The methylcellulose expands in the stomach leaving the person with a filled-up feeling. Also, inflatable bag and tube combinations have been proposed wherein the bag is swallowed into the stomach and the tube attached thereto is used to periodically inflate the bag, particularly just prior to mealtime or during the meal. Once the person has eaten, the bag can be deflated all at once, or it can be deflated gradually over a period of a few hours so as to simulate the condition of digestion occurring and the gradual reduction of stomach contents.
Methylcellulose (MC) is a water-soluble polymer derived from cellulose, the most abundant polymer in nature. As a viscosity-enhancing polymer, it thickens a solution without precipitation over a wide pH range. These functional hydrogels may change their structures as they expose to varying environment, such as temperature, pH, or pressure. MC gels from aqueous solutions upon heating or salt addition (Langmuir 2002; 18:7291, Langmuir 2004; 20:6134). This unique phase-transition behavior of MC enables it a promising functional hydrogel for various biomedical applications (Biomaterials 2001; 22:1113, Biomacromolecules 2004; 5:1917. Tate et al studied the use of MC as a thermoresponsive scaffolding material (Biomaterials 2001; 22:1113. In their study, MC solutions were produced to reveal a low viscosity at room temperature and formed a soft gel at 37° C.; thus making MC well suited as an injectable swellable material. Additionally, using its thermoresponsive feature, MC was reported to harden aqueous alginate as a pH-sensitive based system for the delivery of protein drugs (Biomacromolecules 2004; 5:1917. Some aspects of the invention provide a method and material to fill an internal space of the filler with swellable hydrogel (such as methylcellulose), wherein the hydrogel is a temperature sensitive or pH sensitive hydrogel.
U.S. Pat. No. 4,133,315 issued on Jan. 9, 1979, entire contents of which are incorporated herein by reference, discloses an inflatable bag and tube combination. The tubing remains attached to the bag and inside the esophagus of the person being treated. These tubes are often the cause of erosions and ulcerations of the esophagus. This patent also discloses a gastronomy method, wherein the permanently attached tube used to distend the stomach bag extends through an opening in the stomach wall as well as an opening in the abdomen.
U.S. Pat. No. 4,246,893 issued on Jan. 27, 1981, entire contents of which are incorporated herein by reference, discloses an inflatable bag and tube combination, which is surgically positioned outside and adjacent to the stomach. Upon inflation of the bag, the upper abdomen is distended and the stomach compressed to produce a sense of satiety, which reduces the person's desire to ingest food.
U.S. Pat. No. 4,598,699 issued on Jul. 8, 1996, entire contents of which are incorporated herein by reference, discloses an endoscopic instrument for removing an inflated insert from the stomach cavity of a person being treated for obesity comprising an elongated flexible tube having passageways therein and a holding device at the distal end of the flexible tube that is constructed and arranged to grasp and stabilize the inflated stomach insert.
Certain prior art discloses a gastric stimulator apparatus for stimulating neuromuscular tissue in the stomach, for example, U.S. Pat. No. 6,826,428 issued on Nov. 30, 2004. In one disclosure, it provides a method of regulating gastrointestinal action using a stimulatory electrode and a sensor to provide retrograde feedback control of electrical stimulation to the GI tract or to the stomach.
U.S. Pat. No. 7,020,531 issued on Mar. 28, 2006, entire contents of which are incorporated herein by reference, discloses a device for electrical stimulation of the stomach wall. The device may also have other functional aspects such as a sensor for sensing various parameters of the stomach or stomach environment, or a substance delivery device. In one embodiment, an endoscopic delivery system delivers the functional device thorough the esophagus and into the stomach where it is attached to the stomach wall with the assistance of a suction used to stabilize the tissue of the stomach wall.
U.S. Pat. No. 6,535,764 issued on Mar. 18, 2003, U.S. Pat. No. 7,016,735 issued on Mar. 21, 2006, and U.S. Pat. No. 7,076,305 issued on Jul. 11, 2006, entire contents of which are incorporated herein by reference, disclose a gastric stimulation device comprising: a housing; electronic circuitry contained within the housing; at least one stimulating electrode coupled to the housing and electrically coupled to the electronic circuitry; and an attachment device coupled to the housing and operative to attach the housing within a stomach cavity to a stomach wall so that the at least one stimulating electrode is in electrical contact with the stomach wall; wherein the electronic circuitry is configured to deliver electrically stimulating signals to the stomach through the at least one stimulating electrode.
U.S. Pat. No. 4,694,827 issued on Sep. 22, 1987, entire contents of which are incorporated herein by reference, discloses a balloon insertable and inflatable in the stomach to deter ingestion of food and having, when inflated, a plurality of smooth-surfaced convex protrusions disposed to permit engagement of the stomach wall by the balloon only at spaced localities, for minimizing mechanical trauma of the stomach wall by the balloon.
U.S. Pat. No. 6,746,460 issued on Jun. 8, 2004, entire contents of which are incorporated herein by reference, discloses an expandable device that is inserted into the stomach of the patient that is maintained within by anchoring or otherwise fixing the expandable device to the stomach walls. Such expandable devices have tethering regions for attachment to the one or more fasteners, which can be configured to extend at least partially through one or several folds of the patient's stomach wall. Such fasteners can be formed in a variety of configurations (e.g., helical, elongate, ring, clamp) and they, can be configured to be non-piercing.
Hence, reducing the size of the gastric compartment has been shown to induce weight loss in a significant percentage of people, and the present invention is aimed at a device which non-operatively reduces the size of the gastric compartment and which is easily removed. Further, the invention discloses a gastric space filler device with drug release capability and/or stimulation capability. One aspect of the invention relates to an intragastric balloon system with means for reducing nausea caused by the implant.